fix(streams): system_clock timestamps; dialog manifest + overload-guard consistency sweep

[facontidavide]

Four fixes surfaced by the plugin-authoring audit done for plotjuggler_sdk#151:

1. Genuine bug — wrong clock for receive timestamps (mqtt / udp / zmq)

data_stream_mqtt, data_stream_udp, and data_stream_zmq stamped received messages with std::chrono::high_resolution_clock. That clock aliases steady_clock on MSVC and libc++, so on Windows (which this repo builds for) and macOS the timestamps are nanoseconds since boot, not since the Unix epoch — silently wrong time axes. Switched to system_clock, matching what data_stream_dummy, data_stream_ros2, and data_stream_webrtc already do. Three one-line changes.

2. Latent — missing onValueChanged name-hiding guard (parser_json / parser_protobuf)

Both dialogs override onValueChanged(int) without the fleet-standard using PJ::DialogPluginTyped::onValueChanged;, silently hiding the double overload. Harmless today (neither dialog has a double-valued widget), but a landmine for the next widget added; the other 10 dialogs all carry the guard.

3. Quaternion dialog manifest missing required id

QuaternionDialog::manifest() returned a hand-written literal without id. Now returns the embedded kQuaternionManifest (generated from manifest.json, which has the full metadata), matching every other dialog.

4. Fleet-wide: two-arg PJ_DIALOG_PLUGIN(Class, manifest) migration

All 20 dialog registration sites used the legacy one-arg form; the SDK header explicitly prefers passing the manifest literal so catalog scans can read dialog metadata without instantiating the plugin. Each site now passes the same embedded-manifest constant its manifest() override already returns — verified in scope at every site, no new includes needed. CLAUDE.md and porting_guide.md updated to teach the two-arg form. (data_stream_ros2 hand-rolls its dialogVtableFor<> specialization and has no macro — untouched.)

Validation

• Full fleet build: 168/168 targets clean.
• ctest: 26/26 tests passed.
• Pre-commit hooks (incl. clang-format) passed.

🤖 Generated with Claude Code

[facontidavide]

CI Windows failure — root cause and fix (781e702):

The two-arg PJ_DIALOG_PLUGIN(Class, kManifest) form is broken under MSVC's legacy preprocessor (this repo doesn't set /Zc:preprocessor): __VA_ARGS__ is forwarded into PJ_DIALOG_PLUGIN_SELECT as a single argument, so the arity dispatch picks the one-arg LEGACY branch with the glued pair as ClassName — hence error C2064 (new JsonParserDialog, kJsonManifest()) and error C2912 (dialogVtableFor<Class, &kManifest>). Linux CI passed because GCC/Clang expand the dispatch correctly; the other 18 sites never got compiled before ninja aborted.

Fixed by calling PJ_DIALOG_PLUGIN_WITH_MANIFEST(Class, kManifest) directly at all 20 sites — a plain 2-param macro with identical expansion on every preprocessor. Docs updated.

Upstream note: this is latent in plotjuggler_sdk itself — pj_plugins/dialog_protocol/.../dialog_plugin_base.hpp's PJ_DIALOG_PLUGIN dispatch needs the classic EXPAND(x) x indirection to be MSVC-legacy-PP-safe. Any Windows plugin author using the header's recommended two-arg form hits this. Worth a PATCH fix in the SDK, after which the pretty form works everywhere.